Fatty acid synthase (FASN), the one and only enzyme equipped for fatty acid synthesis, is well expressed in the greater part of human carcinomas. FASN is active in cancer cells, and its inhibition quickly encourages apoptosis in human cancer cells, involving the dependence of cancer cell survival on FASN activity. FASN has some conflicts in prostatic adenocarcinoma (Pca), mainly toward its expression and Gleason’s score.
The aim of the work
The aim of the work is to study the expression of FASN in Pca and find any correlation of its expression with Gleason score and type of specimens.
Materials and methods
Sixty Pca specimens were collected, including 27 core biopsy and 33 radical prostatectomy specimens. Specimens were stained with hematoxylin and eosin stain and re-evaluated. Immunohistochemical was carried out using rabbit polyclonal anti-FASN antibody. Any degree of cytoplasmic reactivity was considered positive. The percentage of positive cells was calculated and graded as follows: 1+ (weak)=less than 10%, 2+ (moderate)=11–50%, and 3+ (strong)=more than 50% tumor cells stained positive. For statistical purpose, the degree of expression has been grouped into two main categories: low, which includes negative and weak expression, and high, which includes moderate and high expression. χ2 test was used in the statistical study of the presented work.
Cytoplasmic FASN expression was detected in 93.3%. Of 60 cases, the degree of reactivity was graded from negative (4/60, 6.6%), weak 18/60, 30%), moderate (22/60, 36.6%), to strong (16/60, 26.6%). There is a significant difference between Gleason score specimens of less than 7 and those of more than or equal to 7, with P value of 0.0338. Of 34 radical prostatectomy specimens, the degree of reactivity was graded from negative (2/34, 5.8%), weak 9/34, 26.4%), moderate (12/34, 35.2%), to strong (11/34, 32.3%). Of 26 core biopsy specimens, the degree of reactivity was graded from negative (2/26, 7.7%), weak (9/26, 34.6%), moderate (10/26, 38.4%), to strong (5/26, 19.2%). There is no significance between radical prostatectomy specimens and core biopsy among all grades of reactivity, with a P value of 0.7079. No significance was obtained between FASN expressions and types of specimens, whether radical prostatectomy specimens or core biopsy, among all grades of reactivity, with a P value of 0.7079 and 0.3490, respectively. The significant difference was obtained in low and high FASN reactivity with the degree of Gleason score, with a P value of 0.0060.
FASN expression in Pca tends to be more expressed in high Gleason score. FASN antibody has been found to be valuable for diagnosing the Pca and must be more addressed with other parameters including prostate-specific antigen, staging, and clinical correlation.